New findings at Stonehenge suggest its stones were erected much earlier than thought, challenging the site's conventional history.
A new excavation puts the stones' arrival at 3000 BC - almost 500 years earlier than originally thought - and suggests it was mainly a burial site.
The latest results are from a dig by the Stonehenge Riverside Project.
It is in conflict with recent research dating construction to 2300 BC and suggesting it was a healing centre.
The 2300 BC date was arrived at by carbon dating and was the major finding from an excavation inside the henge by professors Tim Darvill and Geoff Wainwright.
That dig was the subject of a BBC Timewatch documentary.
The latest theories, putting construction much earlier, result from an excavation at Aubrey Hole 7 - one of a circle of pits surrounding the stones - in August 2008. The researchers believe the pit probably held a standing stone.
The team suggests the 2300 BC date relates to the time when the stones were moved from the outer pits to the centre of the site.
The dig was directed by archaeologists Mike Parker-Pearson, Mike Pitts and Julian Richards for the Stonehenge Riverside Project.
The Aubrey Hole has already been excavated twice. The first time, when discovered in 1920, and again in 1935.
Mike Parker-Pearson, professor of archaeology at Sheffield University, revived an earlier theory that the holes had held bluestones as the evidence of crushed and compacted chalk had been recorded in 1920 in three of the pits.
Professor Parker-Pearson said: "It's very exciting that we have evidence for stones right from its beginnings around 3000 BC.
"That's almost 500 years earlier than anyone had thought.
"These stones were very closely associated with the remains of the dead. There were cremation burials from inside the holes holding the stones and also the areas around them."
The archaeologists suggest that very early in Stonehenge's history there were 56 Welsh bluestones standing in a ring - 87m (285ft) across.
The Stonehenge Riverside Project has been responsible for major excavation within the Stonehenge world heritage site over the past five years.